Gas Exchange in Organisms / Mammalian Lungs: Adaptations / Mecha

Which row of the table describes the best overall conditions for gas exchange in the lungs?

• Large surface area, long diffusion pathway, steep concentration gradient

• Large surface area, short diffusion pathway, steep concentration gradient

• Large surface area, short diffusion pathway, shallow concentration gradient

• Small surface area, short diffusion pathway, shallow concentration gradient

Tags

NGSS.HS-LS2-5

Which sequence correctly describes the process of inspiration in the human respiratory system?

• Diaphragm and external intercostal muscles contract, Volume of thorax increases, Thorax pressure drops, Air is drawn into the lungs down its pressure gradient

• Thorax expands, Thorax pressure drops, Diaphragm and external intercostal muscles contract, Volume of thorax increases

• Air is drawn into the lungs down its pressure gradient, Diaphragm and external intercostal muscles contract, Thorax pressure drops, Volume of thorax increases

• Thorax pressure drops, Volume of thorax increases, Thorax expands, Air is drawn into the lungs down its pressure gradient

Which of the following is a feature of forced expiration?

• The diaphragm contracts.

• The thorax undergoes a drop in pressure.

• The internal intercostal muscles contract.

• The external intercostal muscles contract.

How can the tidal volume of the lungs be measured?

• Spirometer

• Inhaler

• Data logger

• Oxygen meter

An alveolus has several features to allow efficient gas exchange.

Which of the following below matches each feature of gas exchange to the correct label on the alveolus?

• I: High concentration of oxygen to maintain a steep concentration gradient,

  II: One cell thick for short diffusion distance,

  III: Allows gases to dissolve to aid diffusion

• I: High concentration of carbon dioxide to maintain steep concentration gradient, II: Allows gases to dissolve to aid diffusion, III: One cell thick for short diffusion distance

• I: Large surface area, II: High concentration of oxygen to reduce the concentration gradient, III: Thin walls

• I: Allows gases to dissolve to aid diffusion, II: Moist lining, III: Large surface area

Which feature is necessary to maintain a steep concentration gradient for oxygen in the alveoli?

• High concentration of oxygen

• High concentration of carbon dioxide

• One cell thick for short diffusion distance

• Allows gases to dissolve to aid diffusion

What is the purpose of the capillary wall being one cell thick?

• To maintain a steep concentration gradient

• To allow gases to dissolve

• For short diffusion distance

• To reduce the concentration gradient

Why is it important for gases to dissolve in the alveoli?

• To maintain a steep concentration gradient

• To aid diffusion

• To reduce the concentration gradient

• To increase carbon dioxide levels

What is the function of pulmonary surfactant?

• To increase surface tension on the alveolar wall.

• To reduce the diffusion distance across the alveolar wall.

• To stop the alveoli sacs from sticking together.

• To trap microorganisms and prevent infection.

A scientist examines a cross section of the wall of a bronchus under an electron microscope. Which of the following would be observed?

I. Smooth muscle.

II. Cartilage cells.

III. Ciliated cells.

• I and II.

• I and III.

• II and III.

• I, II and III.